News:

Welcome to the CRG Discussion Forum!Forum registration problems: Make sure you enter your email correctly and you check your spam box first. *Then* email KurtS2@gmail for help.Classified ads are not allowed on the forum.

Author
Topic: 68 Z28 Smog Pump Pulley (Read 9931 times)

Question for all the experts.....I have an original 68 Z28 (engine build date of June 19, 1968) that has a smog system that has never been touched, although it has been sitting on a shelf for the last 25 years. Now that I have decided to restore the car back to original, I have been cleaning up the smog system to reinstall it. I had always thought and seen nearly everywhere that the 68 Z28 smog pump was supposed to have the deep groove #3925522 pulley, but mine has the #3927116 pulley. I looked up the setup in the 68 Assembly Manual and under the RPO Z28 section nothing is mentioned about having a different pulley other than what comes standard on all the other V8's with manual transmission and no air conditioner, which is the #3927116 pulley. I looked up the parts manual and it stated the #3925522 pulley was for the 68 396/427 HI Po engines but nothing was mentioned about the 68 302 having anything different other than the #3927116 pulley. Am I missing something here? Could someone possibly tell me why this discrepancy is present in my system or is it actually standard for the #3927116 to be present?

Yeah.....I looked at that pulley chart and I also read Jerry's book and they both state that it should be a #3925522 pulley but like I said.....this system has never been touched so I'm fairly sure that it came from the factory that way. I guess I will just leave it the way it came. Thanks,Sonet

The SERVICE replacement number shown in the GM parts catalog is 3927116. It's possible it may have had the other pulley originally. It could have been in a crash, or possibley replaced because of a service bulletin ect.

Yeah I guess that could be possible. I bought the car in 1972 from the original owner. I talked with him and asked about parts replaced, collision, or any other work. He said the the car had never been in a collision and the only parts that had been replaced was the muffler and tail pipes. Of course that does not mean he told me everything he knew about the car....HA. But it does look original. The date on the smog pump puts it's manufacture around late May of 68 so that should be about right for an original pump. Like I said, I think I will just leave it as it is.....Especially since I saw an original 3925522 pulley for sale on eBay for $950.00. Whoa!!!!

My white survivor 68 Z28 has the 522, most original cars that I've inspected and know they have not been tampered with have had the 522 pulley. That's not to say that a 116 could have been used because of a supply problem. Stranger things have happened. The belt will not stay on if you take it up to 6500 rpm, I know that.

My white survivor 68 Z28 has the 522, most original cars that I've inspected and know they have not been tampered with have had the 522 pulley. That's not to say that a 116 could have been used because of a supply problem. Stranger things have happened. The belt will not stay on if you take it up to 6500 rpm, I know that.

Jerry

Jerry.....do you still have the 3925522 NOS pulley for sale? I noticed on your web site in the NOS and Rare Parts section that it was mentioned as being in stock. Might be interested in getting one from you. I also have noticed that Classic Industries is showing a reproduction for sale and it looks like the original.....Have you seen this one? Thought maybe I might check this one out if you don't have any for sale anymore.

I would leave it alone. I used to get flack over what many told me was the wrong redline tach in a 67 Z I had but it had been there forever so I left it that way. Now I think there is a large cross section of others that also came that way. Makes for nice conversation also....